Not a tundra but wife has a 19 Sequoia which is the full size suv with same power train and running gear as the tundra. It avg about 16 mpg but the motor makes a lot at power. Pulling a 5500 pound camper it still avgs 14.9. The power plant has been out for a long time and they have the bugs worked out.
I almost stopped at the Sequoia because I like a lot of room. Went with the Land Cruiser instead since my last one (still have it) is such a good vehicle. They do like the gas. At 6000lbs. they should. The new one has more bells and whistles than I ever would need, but what the hell. The only option is what kind of floor mats you want. You only live once I hear.
Already have a couple of trucks, but If I was to buy one now, it would be the Tundra for sure.
